Nice one.

I've seen a lot of artists adding them as well.

I really like this... adds an extra level of characterization.

Experimentation. Always relevant!

OMG Rick! O love your Kangaroos! :D
They have such character and they are refreshingly different!
Would love to see more, keep it up man! :)

So cute! <333 I love these body shapes ahhhh very lovely

I love how they look like ;D you should keep experimenting with them ;D

Looks great!

Oh, it's that her former husband/boyfriend?

Very good idea. It gives an added character allmost like an O.Henry trait.
It could allow a longer strip to run faster as the characters would be easier to identify close or far

Yeah, those roos got huge "character".

I really like these characters <3 Would you mind of one of these days I made fanart of them? :D

Please! I love fanart!

that shirt/coat/top seems to do little more than scream, "Here are my boobs! Look at them!"

You certainly have a thing for bottomless women! XD

Amazing.

If that male looking one the "father" and will there be a story of the it?

That's a nice top.

Something about their shirts looks a bit, odd

I'd like to see it with color. It's kinda hard to tell how well it works when it's just in a sketch.

I'm not sure it's quite working, though. The roos look like they could get away with it, but I don't think the current version works with Hildegard. I can't help but think she's got a bad case of muzzle acne, and her bust shot too reminiscent of a bad high school yearbook photo. You might want to make them smaller and less blotchy, perhaps try a stack of lines instead of blotches.